It is desirable to include an anti-corrosion agent in detergent compositions to inhibit the corrosion and discoloration of metal wash baskets in washing machines and to prevent the discoloration of fabrics which come in contact with the wash baskets.
Unbuilt heavy-duty detergent compositions containing minor amounts of corrosion inhibitors are known in the art. For example, see U.S. Pat. No. 4,079,078, issued to Collins on Mar. 14, 1978, which utilizes minor amounts of fatty acid and alkali metal base corrosion inhibitors; U.S. Pat. No. 4,075,118, issued to Gault et al on Feb. 21, 1978, which also utilizes minor amounts of fatty acid corrosion inhibitors; and the copending application of McGrady, Ser. No. 973,254, filed on Dec. 26, 1978, which discloses the use of a mixture of an aromatic triazole and an oligomeric olefinic fatty acid as a corrosion inhibiting system. The above disclosures are incorporated herein by reference.
The present invention embodies the discovery that alkali metal, alkaline earth metal, or ammonium salicylates are especially effective corrosion inhibitors in low or no phosphate heavy-duty detergent compositions.
Accordingly, it is an object of this invention to provide detergent compositions, especially stable liquid compositions, which exhibit excellent pretreatment and through-the-wash fabric cleaning with no or low levels of phosphate materials while delivering improved corrosion inhibition in washing machines.